The genus Beta encompasses economically important root crops such as sugar and table beet.A Beta diversity set including the wild relative B.vulgaris ssp.maritima was grown in the field,and a large phenotypic diversit...The genus Beta encompasses economically important root crops such as sugar and table beet.A Beta diversity set including the wild relative B.vulgaris ssp.maritima was grown in the field,and a large phenotypic diversity was observed.The genomes of 290 accessions were sequenced,and more than 10 million high-quality SNPs were employed to study genetic diversity.A genome-wide association study was performed,and marker-trait associations were found for nine phenotypic traits.The candidate gene within the M locus controlling monogermity on chromosome 4 was previously unknown.The most significant association for monogermity was identified at the end of chromosome 4.Within this region,a non-synonymous mutation within the zinc-finger domain of the WIP2 gene co-segregated with monogermity.This gene plays a regulatory role in AGL8/FUL in Arabidopsis.Intriguingly,commercial hybrids are in a heterozygous state at this position.Thus,the long-sought gene for monogermity was identified in this study.Red and yellow pigmentation due to betalain accumulation in shoots and roots is an important characteristic of table and leaf beets.The strongest associations were found upstream or downstream of two genes encoding Cytochrome P450 and anthocyanin MYB-like transcription factor proteins involved in betalain biosynthesis.Significant associations for Cercospora leaf spot resistance were identified on chromosomes 1,2,7,and 9.The associated regions harbor genes encoding proteins with leucinerich repeats and nucleotide binding sites whose homologs are major constituents of plant-pathogen defense.展开更多
The disease syndrome"basses richesses"(SBR)leads to a significant reduction in sugar beet biomass and sugar content,negatively affecting the sugar economy.The mechanistic understanding regarding growth and p...The disease syndrome"basses richesses"(SBR)leads to a significant reduction in sugar beet biomass and sugar content,negatively affecting the sugar economy.The mechanistic understanding regarding growth and photo-assimilates distribution within the sugar beet taproot diseased with SBR is currently incomplete.We combined two tomographic methods,magnetic resonance imaging(MRI)and positron emission tomography(PET)using 11C as tracer,to non-invasively determine SBR effects on structural growth and photoassimilates distribution within the developing taproot over six weeks.MRI analysis revealed a deformed cross-sectional anatomical structure from an early stage,as well as a reduction in taproot volume and width of inner cambium ring structures of up to 26 and 24%,respectively.These SBR disease effects were also confirmed by post-harvest analysis of the taproot.PET analysis revealed a heterogeneous distribution of labeled photoassimilates for diseased plants:sectors of the taproot with characteristic SBR symptoms showed little to very low ^(11)C tracer signal.The heterogeneity of SBR disease effects is most likely due to a partial inoculation of leaves leading to an uneven distribution of the SBR pathogen in the taproot through the strong vascular interconnection between shoot and root.Also,the pathogen needs to spread non-uniformly within the taproot to explain the observed marked increase of the SBR disease effects over time.Our results indicate that SBR affects photoassimilates sink capacity at an early stage of taproot development.Co-registration of MRI and PET may support an early judging of susceptibility and selection of promising genotype candidates for future breeding programs.展开更多
基金the financial support from the German Research Foundation(Deutsche Forschungsgemeinschaft,DFG)—Project Number 400993799(Project 2 within the Research Training Group 2501 Translational Evolutionary Research,https://gepris.dfg.de/gepris/projekt/400993799)supported by the BMBF-funded de.NBI Cloud,part of the German Network for Bioinformatics(de.NBI)。
文摘The genus Beta encompasses economically important root crops such as sugar and table beet.A Beta diversity set including the wild relative B.vulgaris ssp.maritima was grown in the field,and a large phenotypic diversity was observed.The genomes of 290 accessions were sequenced,and more than 10 million high-quality SNPs were employed to study genetic diversity.A genome-wide association study was performed,and marker-trait associations were found for nine phenotypic traits.The candidate gene within the M locus controlling monogermity on chromosome 4 was previously unknown.The most significant association for monogermity was identified at the end of chromosome 4.Within this region,a non-synonymous mutation within the zinc-finger domain of the WIP2 gene co-segregated with monogermity.This gene plays a regulatory role in AGL8/FUL in Arabidopsis.Intriguingly,commercial hybrids are in a heterozygous state at this position.Thus,the long-sought gene for monogermity was identified in this study.Red and yellow pigmentation due to betalain accumulation in shoots and roots is an important characteristic of table and leaf beets.The strongest associations were found upstream or downstream of two genes encoding Cytochrome P450 and anthocyanin MYB-like transcription factor proteins involved in betalain biosynthesis.Significant associations for Cercospora leaf spot resistance were identified on chromosomes 1,2,7,and 9.The associated regions harbor genes encoding proteins with leucinerich repeats and nucleotide binding sites whose homologs are major constituents of plant-pathogen defense.
基金This study was funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany's Excellence Strategy-EXC 2070-390732324.
文摘The disease syndrome"basses richesses"(SBR)leads to a significant reduction in sugar beet biomass and sugar content,negatively affecting the sugar economy.The mechanistic understanding regarding growth and photo-assimilates distribution within the sugar beet taproot diseased with SBR is currently incomplete.We combined two tomographic methods,magnetic resonance imaging(MRI)and positron emission tomography(PET)using 11C as tracer,to non-invasively determine SBR effects on structural growth and photoassimilates distribution within the developing taproot over six weeks.MRI analysis revealed a deformed cross-sectional anatomical structure from an early stage,as well as a reduction in taproot volume and width of inner cambium ring structures of up to 26 and 24%,respectively.These SBR disease effects were also confirmed by post-harvest analysis of the taproot.PET analysis revealed a heterogeneous distribution of labeled photoassimilates for diseased plants:sectors of the taproot with characteristic SBR symptoms showed little to very low ^(11)C tracer signal.The heterogeneity of SBR disease effects is most likely due to a partial inoculation of leaves leading to an uneven distribution of the SBR pathogen in the taproot through the strong vascular interconnection between shoot and root.Also,the pathogen needs to spread non-uniformly within the taproot to explain the observed marked increase of the SBR disease effects over time.Our results indicate that SBR affects photoassimilates sink capacity at an early stage of taproot development.Co-registration of MRI and PET may support an early judging of susceptibility and selection of promising genotype candidates for future breeding programs.
